Abstract: The well-known model of the triangle diagrams with D∗ ¯DD∗ and ¯D∗D ¯D∗ mesons in the loops is compared with the modern data on the amplitude of the X(3872) → π0χc1(1P ) decay. Considering the X(3872) object as a χc1(2P ) charmonium state, we introduce a parameter ξ characterizing the scale of the isotopic symmetry violation in this decay and find a lower limit of ξ ' 0.0916. The model incorporates the only fitted parameter associated with the form factor. We analyze in detail the influence of the form factor on the amplitude X(3872) → π0χc1(1P ) and on the parameter ξ. As the suppression of the amplitude by the form factor increases, ξ increases. Because the X(3872) resonance is located practically at the threshold of the D0 ¯D∗0 channel, the amplitude of X(3872) → π0χc1(1P ) turns out to be proportional to √md − mu. Using the estimating values for the coupling constants gXD ¯D∗ , gχc1D ¯D∗ , and gD∗0D∗0π0 , we show that the model of the triangle loop diagrams is in reasonable agreement with the available data. Apart from the difference in the masses of neutral and charged charmed mesons, any additional exotic sources of isospin violation in X(3872) → π0χc1(1P ) (such as a significant difference between the coupling constants gXD0 ¯D∗0 and gXD+D∗− ) are not required to interpret the data. This indirectly confirms the isotopic neutrality of the X(3872), which is naturally realized for the c¯c state χc1(2P ).

Cite: Achasov N.N. , Shestakov G.N.
Toward an estimate of the amplitude X(3872) → π0χ c1(1P)
Physical Review D: Particles and fields. 2024. V.109. N3. 036028 :1-11. DOI: 10.1103/PhysRevD.109.036028 WOS Scopus РИНЦ OpenAlex

Dates:

Submitted:	Jan 10, 2024
Accepted:	Feb 2, 2024
Published print:	Feb 26, 2024
Published online:	Feb 26, 2024

Identifiers:

Web of science:	WOS:001181678500007
Scopus:	2-s2.0-85188214492
Elibrary:	66391090
OpenAlex:	W4392155416

Citing:

DB	Citing
OpenAlex	4
Scopus	4
Web of science	2
Elibrary	3

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